Positron Emission Tomography in Psychiatric Research

Since the first visualization and quantification of D2 dopamine receptors with positron emission tomography (PET), nuclear imaging technology with PET and single photon emission computed tomography (SPECT) has led to an enormous gain in knowledge about the neurobiology and treatment of psychiatric disorders. With the development of selective high-affinity tracers for a large variety of neurotransmitter receptors and other targets such as enzymes it became possible to study normal and pathological neurochemistry in vivo in the human brain. In neuropsychopharmacology, PET led to a profound understanding of the relationships between dosages and plasma concentrations of psychotropic drugs on the one hand and occupancy of target receptors and related clinical effects and side effects on the other hand. Furthermore, nuclear imaging helped to generate hypotheses regarding the mechanism of action of certain compounds. This presentation will illustrate current approaches in PET research and their clinical applications with applications from research on schizophrenic and addictive disorders, especially alcohol dependence. It will cover a broad range of transmitter systems like dopamine (receptors and metabolism), serotonin, GABA, and opioid, as well as glucose metabolism as studied with fluorodesoxyglucose. The characterization of antipsychotics with PET will exemplify current research strategies in neuropsychopharmacology. PET, like no other method, is suitable to display in vivo the neurobiochemistry of psychiatric disorders and the psychopharmacology that is used to treat those disorders.